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Content-Based Adaptive Spatio-Temporal Methods for MPEG Repair

J. Park, D.-C. Park, R.J. Marks, M.A. El-Sharkawi
2004 IEEE Transactions on Image Processing  
In the spatial algorithm, missing block recovery and edge extention are performed by pixel replacement based on range constraints imposed by surrounding neighborhood edge information and structure.  ...  Index Terms-Block loss recovery, H.263, motion vector (MV) recovery, MPEG, spatial and temporal error concealment, video communication.  ...  In the spatial algorithm, missing block recovery and edge extention are performed by pixel replacement based on range constraints imposed by surrounding neighborhood edge information and structure.  ... 
doi:10.1109/tip.2003.822615 pmid:15326849 fatcat:rdt6zzuep5ehnahfmptpdu2m3e

Spatial and Temporal Error Concealment Techniques for Video Transmission Over Noisy Channels

W.-Y. Kung, C.-S. Kim, C.-C.J. Kuo
2006 IEEE transactions on circuits and systems for video technology (Print)  
Based on selective directional interpolation, our method can recover both smooth and edge areas efficiently.  ...  Our method adopts a decoder-based error tracking model and combines several concealment modes adaptively to minimize the mean square error of each pixel.  ...  of motion vectors of adjacent MBs. 4) Choose the motion vector based on the side matching criterion [19] , [20] .  ... 
doi:10.1109/tcsvt.2006.877391 fatcat:jliwfx6vq5getfw7iucd5scdse

Stereo Matching with Direct Surface Orientation Recovery

H. Hattori, A. Maki
1998 Procedings of the British Machine Vision Conference 1998  
While area-based stereo matching is an essential technique in the recovery of the dense 3D shape, conventionally it uses square windows based on the implicit assumption that intensity patterns surrounding  ...  Through experiments we demonstrate that our algorithm indeed realizes more precise recovery of the 3D shape than do conventional ones while being applicable to various images.  ...  Conventional area-based stereo matching employs a "square window" to measure the similarity or non-similarity among the different image regions.  ... 
doi:10.5244/c.12.36 dblp:conf/bmvc/HattoriM98 fatcat:mkyzqls52fgpfgxksixcypfe3y

Tracking Cataract by the Four-Line Method

K. J. Hanna
1988 Procedings of the Alvey Vision Conference 1988  
The application is the analysis of cataract motion in the human eye lens. Images are recorded using retro-illumination photography.  ...  A procedure for performing image registration and optic flow recovery using the same four-line algorithm is presented. Several examples of the algorithm output are given.  ...  ACKNOWLEDGEMENTS We would like to thank Guy Scott for our invaluable conversations concerning the implementation of his four-line motion algorithm. We would also like to thank Professor  ... 
doi:10.5244/c.2.39 dblp:conf/bmvc/HannaT88 fatcat:xyfxe67ixnhkxei455vmoakx4y

Tracking cataract by the 'four-line' method

K.J. Hanna, L Tarassenko
1989 Image and Vision Computing  
The application is the analysis of cataract motion in the human eye lens. Images are recorded using retro-illumination photography.  ...  A procedure for performing image registration and optic flow recovery using the same four-line algorithm is presented. Several examples of the algorithm output are given.  ...  ACKNOWLEDGEMENTS We would like to thank Guy Scott for our invaluable conversations concerning the implementation of his four-line motion algorithm. We would also like to thank Professor  ... 
doi:10.1016/0262-8856(89)90021-8 fatcat:rtfwz3febbaadkofsoltzysh5y

Feature-adaptive motion tracking of ultrasound image sequences using a deformable mesh

Fai Yeung, S.F. Levinson, Dongshan Fu, K.J. Parker
1998 IEEE Transactions on Medical Imaging  
A novel deformable block matching algorithm, making use of a Lagrange element for higher-order description of local motion, is proposed to estimate a nonrigid motion vector at each node.  ...  Experiments based on ultrasound images of a tissuemimicking phantom and a muscle undergoing contraction, and on computer simulations, have shown that the proposed algorithm can successfully track nonrigid  ...  Wang and Lee [11] used an iterative gradient-based nodal motion vector esti-mation method based on a deformable mesh that takes image gradient information into account.  ... 
doi:10.1109/42.746627 pmid:10048851 fatcat:6a6fgsmdjvazhfn4vaid2rcoji

Real-time 2(1/2)-D head pose recovery for model-based video-coding

M.D. Cordea, E.M. Petriu, N.D. Georganos, D.C. Petriu, T.E. Whalen
2001 IEEE Transactions on Instrumentation and Measurement  
The resulting motion tracking system works in a realistic environment without makeup on the face, with an uncalibrated camera, normal lighting conditions, and an unknown background.  ...  The described method uses a two-dimensional (2-D) elliptical head model, regionand edge-based matching algorithms, and a linear Kalman filter estimator.  ...  (2) where are the matching scores based on intensity gradients and object color, respectively.  ... 
doi:10.1109/19.948316 fatcat:vnegchepbvhn3jnnhv7tfjouta

A spatio-temporal concealment technique using boundary matching algorithm and mesh-based warping (BMA-MBW)

L. Atzori, F.G.B. De Natale, C. Perra
2001 IEEE transactions on multimedia  
Index Terms-Affine transform, boundary matching algorithm, mesh-based processing, spatial and temporal concealment, video concealment. I.  ...  The first step is achieved by a fast matching algorithm, for a high precision is not needed, while the second step uses an affine transform applied to a deformable mesh structure.  ...  The problem is then to search the best motion vector for the damaged area, based on the motion of surrounding blocks.  ... 
doi:10.1109/6046.944476 fatcat:te6rsubafbet7nbuf7c3ee6pxi

Affine models for motion and shape recovery

Chiou-Shann Fuh, Petros Maragos, Petros Maragos
1992 Visual Communications and Image Processing '92  
The 2-D displacement vectors are estimated as parameters of a 2-D affine model that generalizes standard block matching by allowing affine shape deformations of image blocks and affine intensity transformations  ...  This paper presents an affine model for 3-D motion and shape recovery using two perspective views and their relative 2-D displacement field.  ...  Acknowledgements This research work was supported by a National Science Foundation Presidential Young Investigator Award under NSF Grant MIP-86-58150 with matching funds from DEC and Xerox, by TASC, and  ... 
doi:10.1117/12.131421 fatcat:3oibbyxt55bdrmvx75i5jka43a

Robust Real-Time Visual SLAM Using Scale Prediction and Exemplar Based Feature Description

Denis Chekhlov, Mark Pupilli, Walterio Mayol, Andrew Calway
2007 2007 IEEE Conference on Computer Vision and Pattern Recognition  
This is achieved in real-time by using a SIFT-like spatial gradient descriptor in conjunction with efficient scale prediction and exemplar based feature representation.  ...  The key component is a novel feature description method which is both fast and capable of repeatable correspondence matching over a wide range of viewing angles and scales.  ...  Acknowledgements This work was funded by ORSAS UK and the EPSRC Equator IRC.  ... 
doi:10.1109/cvpr.2007.383026 dblp:conf/cvpr/ChekhlovPMC07 fatcat:75x3rasldzavfbdavqskwjttse

Displacement field estimation and image segmentation using block matching enhanced by a neural network

Yong-Sheng Chen, Chiou-Shann Fuh
1996 Spatial Vision  
The block-matching method plays an important role in displacement field estimation due to its simplicity, achievement of long-range motion, and robustness to noise.  ...  A modified block matching is used to compute a more accurate displacement field by utilizing the segmentation information embedded in the neural network.  ...  One segmentation algorithm is based on region growing to aggregate all the neurons connected by strong synapses.  ... 
doi:10.1163/156856896x00042 fatcat:thmb4g7unnfdrhayyxa57ix3qu

Keyframe-based monocular SLAM: design, survey, and future directions

Georges Younes, Daniel Asmar, Elie Shammas, John Zelek
2017 Robotics and Autonomous Systems  
, poorly textured scenes, repetitive textures, map maintenance, and failure recovery.  ...  Although filter-based monocular SLAM systems were common at some time, the more efficient keyframe-based solutions are becoming the de facto methodology for building a monocular SLAM system.  ...  Silveira et al. (2008) proposed a real-time direct solution by assuming large patches surrounding regions of high intensity gradients as planar; and then performing image alignment by minimizing the photometric  ... 
doi:10.1016/j.robot.2017.09.010 fatcat:b6ilgshsinckjdnlsozmjppkly

Image registration for image-based rendering

A.M.K. Siu, R.W.H. Lau
2005 IEEE Transactions on Image Processing  
Index Terms-Image-based rendering (IBR), image matching, image registration, object recognition.  ...  Based on these requirements, we present a novel image registration technique to automatically recover the geometric proxy from reference images.  ...  ACKNOWLEDGMENT The authors would like to thank the anonymous reviewers for their helpful and constructive comments on this paper. They would also like to thank A. Wan for some of the discussions.  ... 
doi:10.1109/tip.2004.840690 pmid:15700529 fatcat:y4gt2iwryrfqdjig4fv3qsy7k4

A Locally Adaptive Regularization Based on Anisotropic Diffusion for Deformable Image Registration of Sliding Organs

Danielle F. Pace, Stephen R. Aylward, Marc Niethammer
2013 IEEE Transactions on Medical Imaging  
We show that motion discontinuities caused by sliding can be effectively recovered, unlike conventional regularizations that enforce globally smooth motion.  ...  In particular, we apply the method for respiratory motion estimation in longitudinal thoracic and abdominal computed tomography scans.  ...  Since deformable image registration based on image match alone is ill-posed, a regularization term is added to the registration cost function to encourage plausible displacement fields based on some prior  ... 
doi:10.1109/tmi.2013.2274777 pmid:23899632 pmcid:PMC4112204 fatcat:jhoh3nsbgzff5fugih6nw6xati

Feature Detector and Descriptor for Medical Images

Dusty Sargent, Chao-I Chen, Chang-Ming Tsai, Yuan-Fang Wang, Daniel Koppel, Josien P. W. Pluim, Benoit M. Dawant
2009 Medical Imaging 2009: Image Processing  
Based on experiments with various types of medical images, we combined, adjusted, and built on methods and parameter settings employed in both algorithms.  ...  Finally, keypoints are described with an orientation-normalized distribution of gradient responses at the assigned scale, and the feature vector is normalized for contrast invariance.  ...  A dominant orientation is determined for each keypoint, which is then described by a distribution of gradient responses in an orientation-aligned window surrounding the keypoint.  ... 
doi:10.1117/12.811210 dblp:conf/miip/SargentCTWK09 fatcat:sgclif2qnzcjtdi6x4rvfkpm2q
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